Wiki Redirects and Page Renaming

Added the ability to rename existing pages.
[[!redirects Some Page Name]] redirects Wikilinks [[Some Page Name]] to
  the current page (assuming "Some Page Name" does not exist).
  Real pages trump redirects (though this may change, depending on 
  user feedback).

lib/chunks/redirect.rb

@@ -0,0 +1,21 @@
+require 'chunks/wiki'
+
+#      [[!redirects Foo]]
+# redirects Wikilinks for the (nonexistent) page "Foo" to this page.
+# If "Foo" exists, then the Redirect has no effect. But if "Foo"
+# does not exist, then a Wikilink [[Foo]] will produce a link to this
+# page, rather than produce a create-a-new-page link. 
+
+class Redirect < WikiChunk::WikiReference
+
+  REDIRECT_PATTERN = /\[\[!redirects\s+([^\]\s][^\]]*?)\s*\]\]/i
+  def self.pattern() REDIRECT_PATTERN end
+
+  def initialize(match_data, content)
+      super
+      @page_name = match_data[1].strip
+      @link_type = :redirect
+      @unmask_text = ''
+  end
+
+end